Linux From Scratch - Version GIT-20210406-g8186f16b0

Chapter 5. Compiling a Cross-Toolchain

5.6. Libstdc++ from GCC-10.2.0, Pass 1

Libstdc++ is the standard C++ library. It is needed to compile C++ code (part of GCC is written in C++), but we had to defer its installation when we built gcc-pass1 because it depends on glibc, which was not yet available in the target directory.

Approximate build time: 0.4 SBU
Required disk space: 953 MB

5.6.1. Installation of Target Libstdc++

[Note]

Note

Libstdc++ is part of the GCC sources. You should first unpack the GCC tarball and change to the gcc-10.2.0 directory.

Create a separate build directory for libstdc++ and enter it: 

mkdir -v build
cd       build

Prepare libstdc++ for compilation: 

../libstdc++-v3/configure           \
    --host=$LFS_TGT                 \
    --build=$(../config.guess)      \
    --prefix=/usr                   \
    --disable-multilib              \
    --disable-nls                   \
    --disable-libstdcxx-pch         \
    --with-gxx-include-dir=/tools/$LFS_TGT/include/c++/10.2.0

The meaning of the configure options:

--host=...

Specifies that the cross compiler we have just built should be used instead of the one in /usr/bin.

--disable-libstdcxx-pch

This switch prevents the installation of precompiled include files, which are not needed at this stage.

--with-gxx-include-dir=/tools/$LFS_TGT/include/c++/10.2.0

This is the location where the C++ compiler should search for the standard include files. In a normal build, this information is automatically passed to the libstdc++ configure options from the top level directory. In our case, this information must be explicitly given.

Compile libstdc++ by running: 

make

Install the library: 

make DESTDIR=$LFS install

Details on this package are located in Section 8.26.2, “Contents of GCC.”